Apparatus for treating liquid with alpha gas



May 24, 1932.

F. w. MACLENNAN APPARATUS FOR TREATING LIQUID WITH A GAS Filed July 15,1930 2 Sheets-Sheet l INVENTOR Fmnh' lfl'Mwclennan BY W M ATTORNEYS y24, 1932- F. w. MACLENNAN 1,859,781

APPARATUS FOR TREATING LIQUID WITH A GAS Filed July 15, 1930 2Sheets-Sheet 2 I. I I I I, ll Ell I I I I I llinfin nv. i=1? INVENTOR eI ATTORNEYS Patented May 24, 1932 UNITED STATES PATENT-OFFICE,

FRANK W. MACLENNAN, OF MIAMI, ARIZONA APPARATUS FOR TREATING LIQUIDWITH-A GAS Application filed July 15, 1930. Serial N'o. 468,015.

My invention relatesto improvements in apparatus for treating liquidwitha gas and more particularly to an improved apparatus for theconcentration of ores by what is commonly known as the flotationprocess, in which the ores'or other substances are subjected'to aerationin .an aqueous separating medium in'the presence of suitable agentsforthe formation of a froth containing valuable portions of said ores orother substances, and thereby separating said values from the barren orrocky constituents thereof.

More particularly the present invent on relates to an improved means forregulatingand controlling the air introduced into flotation machines ofthe cascadeftype.

The principle of operation and novel features of the invention'will beunderstood from the following description, taken in conjunction with theaccompanying drawings, in which similar reference characters refer tosimilar parts throughoutthe several views.-

Fig. 1 is'a longitudinal sectional elevation in-exaggerated proportionof the flotation cell taken on line 11 of Fig. 2.

Fig.2 is a transverse section of the flotation cell taken on line 22 ofFig; l. V

Fig. 3 is a section in detail of the air inlet means. p

F ig.4 is a fragmentary section on line 4-4 ofF1g.3. a

Fig. 5 is a fragmentary section on line 55 v The drawings illustrate onetype of cascade flotation machine equipped with the improvedlmeansfor-regulating and controlling theintroduction of air, embodying my invention. Air under pressure enters themachine through the headers 10,and passes through the primary airslots 12; These primary air slots v 12outlet into a central air chamber 14 running the entire length of the.cell. The cross sectional area of these primary air slots is such thatthey have capacity for carrying several times the total quantity of airrequired for the operation of the machine, thereby insuring @thatsuflicient air is always being supplied to the central air chamher tominimize any local fluctuations in air pressure occasionedby varying thesize of the discharge openings to be presently described outletting fromsuch chamber to the pulp body. Openings 16, of suitable size and atsuitable intervals, are provided at the top of the air chamber 14. Afterpassing through these openings 16 the air finally exits between theflexible rubber strips 20 into the apparatus at the base of the air-liftchamber 18. h The sliding valves 22 are also provided with openings 16a.These valves 22 are seated in position against the inside of the top ofthe air chamber 14 by means of springs 24, which are secured to the cellbottom at 26. These springs 24 have the effect of providing a flexiblebase on which the sliding valves 22 slide and at the same time preventan accumulation of dirt under them and keep the valves 22snuglyseatedagainst the openings 16 inthe top of the air chamber 14. 1

Along each side of the air chamber 14 are secured the strips of pure gumrubber 20 which come together at the top, as shown at 28. While themachine is operating, these rubber strips 20 are held apart by the airpressure and the air outlets between them in the form of a substantiallycontinuous sheet. When the air is shut off these strips come to gether,making a seal which prevents the pulp from entering the air chamber. Thevalves 22 which require only a slight movement to open or close theopenings 16, are operated by rods 30 attached to the ends of the valves.

The rods 30 pass through stufiing boxes 32 to prevent escape of air andare provided with threads and threaded hand wheels 34 by which means thevalves 22 may be conveniently moved horizontally to open or ,closeoradjust the size of the openings 16 with extreme nicety. r

The fragmentary section Fig. 4 shows the valves 22 in three differentpositions. At 44, the openings 16 are entirely open to the passage ofair. .At46, they are half closed and at 48, they are entirely closed. vPartitions 36 are introduced at intervalsin the primary air slots .12 inorder tovprevent collapse of the slots and are staggered as shownin Fig..5.

now in current use, it is important to have separate control of the airvolume in diiierent parts of the cell. For example, in arougher cell 100feet long, it is desirable to use asmaller quantity of air in the firstthird of the cell Where a high grade concentrate is required and alarger quantity of air in the rest of the cellwhere it is importanttomake clean tailings regardless of the grade of the concentrate. InFig. 1 is shown a longitudinal section of a flotation cell in, which theconcentrate is removed separately from three compartments of thecell, asindicated bythe concentric launders 38 and discharge spouts 40. In orderto regulate the volume ofair to these three compartments, it isnecessary only toi'regula te the air tothet wio end compart ents meansof the hand wheelsfi l, after, getting the proper amount of air throughthe center compartment by regulating, the main valve to the apparatus,aslindicaited at. 42.

i I have found thatthe regulation ofthe: volume 'o fair, entering theflotation cellby the accurate control of size of thefopeninge. throughwhich the air exits directly orsub f stantially directly into the pulp,results in a s teadi erflow of air anda better distribution of air in'the flotation cell than is. the, case where the'volume ofairto the cellis regulated by valves placed at some distancefrom the ex t openingsinto the cell.v

I havje als'o found that uniformdistribu tion of air-in theflotationcell is facilitated by providing means for leading I air toffchev zoneimmediately in front of such openingsin sub-. stantially greater volumethan it. caii' be discharged through l such openings and I so in strunga constanthead of airfroin thesprimary source ofair under pressure whichthe pressureslocally preyailing will notfluctuate,

widely with c hangesjin the size of such air z'iit pf nin the-"pr 636m;invention a be n Ed scribed {with particular? f f l cev to, ,a ,flOfiaftion, cell operating on: the cascade principle, it 'will be understoodthat it is capable of.a-p.-.

plication to other types 0: cellsinf vwhich uplift action to beproduced. Itwill be fur-. ther understood that various changes in. thedetails of thelconstructionmaybe madewitlr. out idepart ingfrom theinvention, which is not toi be deemed as limited other than as indicatedthe: appended claims. I

I laim 1 I i 1. Ina-n ore flotation apparatus, an elongated tankadaptedto contain! ore vpulp, a

longitudinally-extending. uplift chamber within 3 said tank, an airchamber, disposed beneath the lower end of ,said upligft chamiher andsubstantially coterminous as to en th ith Said, uplift hamb jrrme n d pntheupper side, of said air chamber e el -Rin su an ial y n qi shitthrough which to inject air in an ,upward. ire i nt ru e ee e edJ i h itank, thereby producing an upward circulation of pulp through saiduplift chamber, said means being responsive to changes in the pressureat which air is supplied to said air chamber for opening and closingsaid slot, and Valve means immediately adjacent to and beneath saidslot-forming means for controlling, the volume of; air; supplied throughsaid slot.

2. In an ore flotation apparatus, an elongated: tank; adapmd! to;contain ore pulp, a longitudinally-extending uplift chamber Withinsaid-tank, an-air-chamber disposed beneath the lower end of said upliftchamber and substantially coterminous as to length w h: id. pli t hmber;,. id. ir, h mb e ng-p v dedon i s pp r,s de th-aseries t eles lypac d. Qn ni sa v lve membe mquntedrinvsaid air chamber, tor;controlling,

e za r; m ghsa nn nings and means di p se mme iat ly. amass. o, and aboSaid; Qu ni e f r. definin t ubstantially wn im l t hrou h. h ch to, j cai i e u -tant alla on uous-sheet n "amp.-

warld' direction into pulp contained within 90.;

l pl di h eugh idi n ings rz pen-r as:

ing and closing sa d slot.

nfil app rabw ot atin liqui w a a a anls nte e ntain quid; a a r c iv ngh mber; spe ed adiacen t el ws r; end o aid a kl ndi n s ant l yt ter?-m nolis. r e sl th ith ai in a dim nsio Of saidnk, .m ans isn sed, .1.1he uppe ide-0fs idses ec v ngi hamb rr d i ing a substantially,continuous slot, through which to ject gas n. ani pwa td dire t on. 1

into, qu dntai ed ithing a d t i means being, responsive to, changes ;inthe a P s re t. i h gas is upn ied tisa d ga receiving chamber'foropening and closing;

aid i ndz alve m anst mm di e y d- 1 0 jacent to and beneath saidslotforming, ns, er ltr li J g-r ha volum 0i :gassupplied through saidslot.

nfi para us:fer re t n -iliqeidiwi a teas i l; asapeem vqemtaim.- qiiidgass rib tin me n ompri in wees e l s ham er; o i e tj it u aid tank, sag s-r ce g amber bein pr v d. i h a' series of "closely spaced jopeningsfor disaea i w 'e qu drava i memben 12 mounted adjacent said openingsand"subjstantially coterminous as tolengthf with said seriesof-fopenings for simultaneously ad justing the e'fiectiye size-ofall of,the openings in-saidseries, and means disposed '.im-,

mediately. adjacent: tosaid; valve member and. said openings fordefining a substantially continuous .slot. thnoughi \which\to inject gasas a substantially continuoussheet into liquid contained 1 within-nsaidqtank saidzs1otrforming means being responsive to changes in thepressure at which gas is supplied through said openings for opening andclosing'smd slot.

July, 1930.

FRANK W. MACLENN AN.

